Prior art includes the Conical Split-Image Microscopic Lens mentioned above. This stage lens has a code designation of M:RR-RR-RT:C (M--microscopic stage lens, R--refracting section of a component lens, T--transmitting section of a component lens, and C--concentrating stage lens).
The two component lenses of the disclosure have a code designation of RT-RT and when inserted between the patented component lenses change the code designation to M:RR-RT-RT-RR-RT:C.